This invention relates to a method of and apparatus for applying a string to a tampon pledget and more particularly to a method of and apparatus for automatically knotting and attaching strings to tampon pledgets in relatively high speed production.
Strings may be attached to tampon pledgets using various methods. Some of these methods may be accomplished manually and others require various apparatus. Many of these apparatus are highly complex, requiring significant initial capital expenditures. Examples of such apparatus include those disclosed in U.S. Pat. No. 4,144,623 issued Mar. 20, 1979, entitled, xe2x80x9cProcess for the Production of Tampon Blanksxe2x80x9d; U.S. Pat. No. 4,490,894 issued Jan. 1, 1985, entitled, xe2x80x9cApparatus for Attaching a Withdrawal Cord to a Tamponxe2x80x9d; U.S. Pat. No. 5,566,435 issued Oct. 22, 1996, entitled, xe2x80x9cMethod of Attaching a Tampon Withdrawal Cord with an Overhand Hitch Knotxe2x80x9d; and U.S. Pat. No. 6,213,040B1 issued Apr. 10, 2001, entitled, xe2x80x9cApparatus for High-Speed Lacing of an Articlexe2x80x9d. The complexity of these apparatus can make maintenance and repair of the apparatus difficult and costly. Thus, there is a need for a relatively simple high speed apparatus and method for attaching strings to tampon pledgets.
In general, a method of the present invention is for applying a withdrawal string to a tampon pledget having opposite faces and includes positioning the string to extend across one of said faces of the pledget, said string thereby having a generally central portion on said one face and reaches extending on both sides of the pledget, acting on said reaches pneumatically to form the string into a loop looped around the pledget, securing together the end portions of the reaches in the loop, and moving the secured-together end portions through the pledget thereby bringing part of the loop including the secured-together end portions thereof to extend out from said one face of the pledget.
In general, apparatus of the invention includes a string feeder for positioning a string to extend across one of the faces of the pledget, said string thereby having a generally central portion on said one face and reaches extending on both sides of the pledget, a pneumatic system operable on said reaches pneumatically to form the string into a loop looped around the pledget, a knotter for knotting together end portions of the reaches in the loop, and a probe movable to drive the knotted end portion of the loop through the pledget thereby bringing part of the loop including the secured-together end portions thereof to extend out from said one face of the pledget.
Other features will be in part apparent and in part pointed out hereinafter.